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  Beauty can come after death — well, at least after the death of a star. The image captured above, taken by the Gemini Observatory, showcases the planetary nebula known as CVMP 1, which is the outcome of a main-sequence star that blew off its outer layers as it ballooned into a red giant. This cosmic wonder doesn't have a long lifespan, though. Its hourglass shape will only last about 10,000 years. And one day, the star will cool down, causing its hourglass form to fade from view.   CVMP 1 is located about 6,500 light years away in the constellation of Circinus. This planetary nebula is formed mostly of enriched helium and nitrogen and is one of the largest planetary nebulae known to astronomers. Despite their name, planetary nebulae aren’t formed from planets. Instead, their name comes from the round, planet-like appearance some stars had when viewed through early telescopes. Planetary nebulae also take on a wide variety of...

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A plume of gas nearly the size of our solar system erupts from Betelgeuse's surface in this artist's illustration of real observations gathered by astronomers using the Very Large Telescope in Chile.   If you stargaze on a clear winter night, it’s hard to miss the constellation Orion the Hunter, with his shield in one arm and the other arm stretched high to the heavens. A bright red dot called Betelgeuse marks Orion’s shoulder, and this star's strange dimming has captivated skygazers for thousands of years. Aboriginal Australians may have even worked it into their oral histories.   Today, astronomers know that Betelgeuse varies in brightness because it’s a dying, red supergiant star with a diameter some 700 times larger than our Sun. Someday, the star will explode as a supernova and give humanity a celestial show before disappearing from our night sky forever. That eventual explosion explains why astronomers got excited when Betelgeuse start...

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How many planets are there in the universe?

Thursday, February 13th 2020 10:04 AM

  Astronomers estimate that there is roughly one exoplanet per star in our galaxy. Of course, some stars have many planets – our own Sun has eight. And some stars have none. But if a star lives long enough, forming planets seems to be the rule, rather than the exception.That doesn’t mean astronomers can map all of those billions of stars though. When it comes to exoplanets that have been measured or counted in some way, the numbers are much smaller.The running counter of known exoplanets – as of this writing – stands at 4,108 confirmed worlds. But astronomers are surprisingly good at figuring out what they can’t see. They know that their telescopes aren’t powerful or precise enough to see the stealthiest planets – those that are very small, very far from their stars, or around stars very far from Earth. And conversely, there are regions of space where astronomers are pretty confident they’ve...

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This huge, distant galaxy formed all its stars really fast

Thursday, February 6th 2020 03:20 PM

  Extra-massive galaxies are rare, though not unheard of, in the early universe. Now, a team of astronomers has identified a huge galaxy that had to have formed its stars super fast — more than 1000 suns’ worth of stars per year at its peak — so that it was done making stars just 1.8 billion years after the Big Bang.  Astronomers typically expect that any large galaxies they find in the early universe would still have been forming stars at this time. The new finding shows they likely need to tweak their current models of how such galaxies form and evolve, and when they might finish making stars. The researchers presented their findings in a recent paper published in The Astrophysical Journal Letters.  Fast and furious star formation For astronomers trying to understand our universe’s history, figuring out how galaxies are born and grow is an ongoing puzzle. Part of that puzzle is understanding how large galaxies early in the univer...

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Bubbling convection cells, each about the size of Texas, rise and fall across the Sun's surface.     A new solar telescope in Hawaii has taken its first photo and movie of the Sun. The shots are the highest resolution views of our star yet, showing details on the Sun’s surface as small as about 18 miles in size.The Daniel K. Inouye Solar Telescope is located on the Haleakala volcano on the island of Maui. A primary mirror that's 4 meters (about 13 feet) wide makes this the biggest solar telescope on Earth, and it will be able to resolve smaller details on the Sun than ever before. With the telescope’s sophisticated instruments and high resolution, scientists hope to better understand remaining mysteries about our nearest star. A bubbling star The grainy pattern in the telescope’s “first light” image is the mark of plasma cells on the Sun’s surface. Hot plasma from within the Sun rises to the surface, cools and sinks...

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  Scientists have discovered over 4,000 exoplanets outside of our Solar System, according to NASA’s Exoplanet Archive.Some of these planets orbit multiple stars at the same time. Certain planets are so close to their star that it takes only a handful of days to make one revolution, compared to the Earth which takes 365.25 days. Others slingshot around their star with extremely oblong orbits, unlike the Earth’s circular one. When it comes to how exoplanets behave and where they exist, there are many possibilities.And yet, when it comes to sizes of planets, specifically their mass and radius, there are some limitations. And for that, we have physics to blame.   I am a planetary astrophysicist and I try to understand what makes a planet able to support life. I look at the chemical connection between stars and their exoplanets and how the interior structure and mineralogy of different sized planets compare to each other....

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  As an astronomer, the question I hear the most is why isn’t Pluto a planet anymore? More than 10 years ago, astronomers famously voted to change Pluto’s classification. But the question still comes up. When I am asked directly if I think Pluto is a planet, I tell everyone my answer is no. It all goes back to the origin of the word “planet.” It comes from the Greek phrase for “wandering stars.” Back in ancient times before the telescope was invented, the mathematician and astronomer Claudius Ptolemy called stars “fixed stars” to distinguish them from the seven wanderers that move across the sky in a very specific way. These seven objects are the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn.      When people started using the word “planet,” they were referring to those seven objects. Even Earth was not originally called a planet – but the Sun and Moon were. Sin...

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  Even in a backyard telescope, the four largest moons of Jupiter are big enough to be seen as little specks of light. And while humans have known about these “Galilean satellites” for centuries, there are still a lot of unanswered questions about how the moons formed.  Now, a team of researchers has proposed a possible history for the moons that better explains more of their properties than other models could. The team suggests that the moons grew slowly by collecting pebbles, rather than larger rocks, from around an early Jupiter. This process is like a mini version of how astronomers think our entire solar system formed, with worlds growing from pebbles to planets. And in Jupiter's case, the process can account for the moons’ masses, orbits, ice-to-rock ratios and differences in their internal structures, the researchers report in a recent study published in The Astrophysical Journal.      Growing moons In gene...

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  Saturn’s icy moon Enceladus sports a series of parallel, evenly spaced stripes at its south pole. Scientists believe these stripes are long fissures in the icy shell that covers the moon's subsurface liquid water ocean. But astronomers still aren’t sure how these fissures formed, why they’re so evenly spaced or why other icy worlds don’t have them. Now, a team of researchers has proposed an explanation that could account for all the major questions about this series of fissures. The team published their findings Monday in the journal Nature Astronomy.       Breaking Enceladus' ice Scientists discovered the stripes when the Cassini mission to Saturn noticed something unusual at the moon’s south pole. Plumes were erupting along along a series of features that researchers dubbed “tiger stripes.” "People have been interested in this ever since that was discovered, and it's been in kind of...

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  Bobbing up and down like a carousel horse might not sound like a stable way to orbit a planet, but it works for one little moon of Neptune. The planet's innermost known satellite, Naiad, has a tilted orbit and it moves up-and-down relative to its neighboring moon, Thalassa.  The strange arrangement keeps the two moons steadily on track, despite their close orbits, without getting thrown into Neptune or into space, according to a new study. The finding also helps reveal some of the history behind Neptune’s moons. The researchers reported the discovery in a recent paper in the journal  Icarus.     Orbital resonance The arrangement of the two moons’ orbits is an example of what scientists call an orbital resonance. Repeating patterns in their orbits apply a regular set of gravitational forces to the two moons. In this case, the repeating forces keep the moons in their orbits, but resonances can be disruptive as well.&n...

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